/*
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.2 Copyright (C) Paul Johnston 1999 - 2009
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */

/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
var hexcase = 0 /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad = '' /* base-64 pad character. "=" for strict RFC compliance   */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */

export const md5 = {
  hex_md5(s) { return this.rstr2hex(this.rstr_md5(this.str2rstr_utf8(s))) },
  b64_md5(s) { return this.rstr2b64(this.rstr_md5(this.str2rstr_utf8(s))) },
  any_md5(s, e) { return this.rstr2any(this.rstr_md5(this.str2rstr_utf8(s)), e) },
  hex_hmac_md5(k, d) { return this.rstr2hex(this.rstr_hmac_md5(this.str2rstr_utf8(k), this.str2rstr_utf8(d))) },
  b64_hmac_md5(k, d) { return this.rstr2b64(this.rstr_hmac_md5(this.str2rstr_utf8(k), this.str2rstr_utf8(d))) },
  any_hmac_md5(k, d, e) { return this.rstr2any(this.rstr_hmac_md5(this.str2rstr_utf8(k), this.str2rstr_utf8(d)), e) },
  /*
 * Perform a simple self-test to see if the VM is working
 */
  md5_vm_test() {
    return this.hex_md5('abc').toLowerCase() === '900150983cd24fb0d6963f7d28e17f72'
  },
  /*
 * Calculate the MD5 of a raw string
 */
  rstr_md5(s) {
    return this.binl2rstr(this.binl_md5(this.rstr2binl(s), s.length * 8))
  },
  /*
 * Calculate the HMAC-MD5, of a key and some data (raw strings)
 */
  rstr_hmac_md5(key, data) {
    var bkey = this.rstr2binl(key)
    if (bkey.length > 16) bkey = this.binl_md5(bkey, key.length * 8)

    var ipad = Array(16); var opad = Array(16)
    for (var i = 0; i < 16; i++) {
      ipad[i] = bkey[i] ^ 0x36363636
      opad[i] = bkey[i] ^ 0x5C5C5C5C
    }

    var hash = this.binl_md5(ipad.concat(this.rstr2binl(data)), 512 + data.length * 8)
    return this.binl2rstr(this.binl_md5(opad.concat(hash), 512 + 128))
  },
  /*
 * Convert a raw string to a hex string
 */
  rstr2hex(input) {
    try { hexcase } catch (e) { hexcase = 0 }
    var hex_tab = hexcase ? '0123456789ABCDEF' : '0123456789abcdef'
    var output = ''
    var x
    for (var i = 0; i < input.length; i++) {
      x = input.charCodeAt(i)
      output += hex_tab.charAt((x >>> 4) & 0x0F) +
           hex_tab.charAt(x & 0x0F)
    }
    return output
  },
  /*
 * Convert a raw string to a base-64 string
 */
  rstr2b64(input) {
    try { b64pad } catch (e) { b64pad = '' }
    var tab = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
    var output = ''
    var len = input.length
    for (var i = 0; i < len; i += 3) {
      var triplet = (input.charCodeAt(i) << 16) |
                (i + 1 < len ? input.charCodeAt(i + 1) << 8 : 0) |
                (i + 2 < len ? input.charCodeAt(i + 2) : 0)
      for (var j = 0; j < 4; j++) {
        if (i * 8 + j * 6 > input.length * 8) output += b64pad
        else output += tab.charAt((triplet >>> 6 * (3 - j)) & 0x3F)
      }
    }
    return output
  },
  /*
 * Convert a raw string to an arbitrary string encoding
 */
  rstr2any(input, encoding) {
    var divisor = encoding.length
    var i, j, q, x, quotient

    /* Convert to an array of 16-bit big-endian values, forming the dividend */
    var dividend = Array(Math.ceil(input.length / 2))
    for (i = 0; i < dividend.length; i++) {
      dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1)
    }

    /*
   * Repeatedly perform a long division. The binary array forms the dividend,
   * the length of the encoding is the divisor. Once computed, the quotient
   * forms the dividend for the next step. All remainders are stored for later
   * use.
   */
    var full_length = Math.ceil(input.length * 8 /
                                    (Math.log(encoding.length) / Math.log(2)))
    var remainders = Array(full_length)
    for (j = 0; j < full_length; j++) {
      quotient = this.Array()
      x = 0
      for (i = 0; i < dividend.length; i++) {
        x = (x << 16) + dividend[i]
        q = Math.floor(x / divisor)
        x -= q * divisor
        if (quotient.length > 0 || q > 0) { quotient[quotient.length] = q }
      }
      remainders[j] = x
      dividend = quotient
    }

    /* Convert the remainders to the output string */
    var output = ''
    for (i = remainders.length - 1; i >= 0; i--) { output += encoding.charAt(remainders[i]) }

    return output
  },
  /*
 * Encode a string as utf-8.
 * For efficiency, this assumes the input is valid utf-16.
 */
  str2rstr_utf8(input) {
    var output = ''
    var i = -1
    var x, y

    while (++i < input.length) {
    /* Decode utf-16 surrogate pairs */
      x = input.charCodeAt(i)
      y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0
      if (x >= 0xD800 && x <= 0xDBFF && y >= 0xDC00 && y <= 0xDFFF) {
        x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF)
        i++
      }

      /* Encode output as utf-8 */
      if (x <= 0x7F) { output += String.fromCharCode(x) } else if (x <= 0x7FF) {
        output += String.fromCharCode(0xC0 | ((x >>> 6) & 0x1F),
          0x80 | (x & 0x3F))
      } else if (x <= 0xFFFF) {
        output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
          0x80 | ((x >>> 6) & 0x3F),
          0x80 | (x & 0x3F))
      } else if (x <= 0x1FFFFF) {
        output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
          0x80 | ((x >>> 12) & 0x3F),
          0x80 | ((x >>> 6) & 0x3F),
          0x80 | (x & 0x3F))
      }
    }
    return output
  },
  /*
 * Encode a string as utf-16
 */
  str2rstr_utf16le(input) {
    var output = ''
    for (var i = 0; i < input.length; i++) {
      output += String.fromCharCode(input.charCodeAt(i) & 0xFF,
        (input.charCodeAt(i) >>> 8) & 0xFF)
    }
    return output
  },
  str2rstr_utf16be(input) {
    var output = ''
    for (var i = 0; i < input.length; i++) {
      output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,
        input.charCodeAt(i) & 0xFF)
    }
    return output
  },
  /*
 * Convert a raw string to an array of little-endian words
 * Characters >255 have their high-byte silently ignored.
 */
  rstr2binl(input) {
    var output = Array(input.length >> 2)
    for (var i = 0; i < output.length; i++) { output[i] = 0 }
    for (var i = 0; i < input.length * 8; i += 8) { output[i >> 5] |= (input.charCodeAt(i / 8) & 0xFF) << (i % 32) }
    return output
  },
  /*
 * Convert an array of little-endian words to a string
 */
  binl2rstr(input) {
    var output = ''
    for (var i = 0; i < input.length * 32; i += 8) { output += String.fromCharCode((input[i >> 5] >>> (i % 32)) & 0xFF) }
    return output
  },
  /*
 * Calculate the MD5 of an array of little-endian words, and a bit length.
 */
  binl_md5(x, len) {
  /* append padding */
    x[len >> 5] |= 0x80 << ((len) % 32)
    x[(((len + 64) >>> 9) << 4) + 14] = len

    var a = 1732584193
    var b = -271733879
    var c = -1732584194
    var d = 271733878

    for (var i = 0; i < x.length; i += 16) {
      var olda = a
      var oldb = b
      var oldc = c
      var oldd = d

      a = this.md5_ff(a, b, c, d, x[i + 0], 7, -680876936)
      d = this.md5_ff(d, a, b, c, x[i + 1], 12, -389564586)
      c = this.md5_ff(c, d, a, b, x[i + 2], 17, 606105819)
      b = this.md5_ff(b, c, d, a, x[i + 3], 22, -1044525330)
      a = this.md5_ff(a, b, c, d, x[i + 4], 7, -176418897)
      d = this.md5_ff(d, a, b, c, x[i + 5], 12, 1200080426)
      c = this.md5_ff(c, d, a, b, x[i + 6], 17, -1473231341)
      b = this.md5_ff(b, c, d, a, x[i + 7], 22, -45705983)
      a = this.md5_ff(a, b, c, d, x[i + 8], 7, 1770035416)
      d = this.md5_ff(d, a, b, c, x[i + 9], 12, -1958414417)
      c = this.md5_ff(c, d, a, b, x[i + 10], 17, -42063)
      b = this.md5_ff(b, c, d, a, x[i + 11], 22, -1990404162)
      a = this.md5_ff(a, b, c, d, x[i + 12], 7, 1804603682)
      d = this.md5_ff(d, a, b, c, x[i + 13], 12, -40341101)
      c = this.md5_ff(c, d, a, b, x[i + 14], 17, -1502002290)
      b = this.md5_ff(b, c, d, a, x[i + 15], 22, 1236535329)

      a = this.md5_gg(a, b, c, d, x[i + 1], 5, -165796510)
      d = this.md5_gg(d, a, b, c, x[i + 6], 9, -1069501632)
      c = this.md5_gg(c, d, a, b, x[i + 11], 14, 643717713)
      b = this.md5_gg(b, c, d, a, x[i + 0], 20, -373897302)
      a = this.md5_gg(a, b, c, d, x[i + 5], 5, -701558691)
      d = this.md5_gg(d, a, b, c, x[i + 10], 9, 38016083)
      c = this.md5_gg(c, d, a, b, x[i + 15], 14, -660478335)
      b = this.md5_gg(b, c, d, a, x[i + 4], 20, -405537848)
      a = this.md5_gg(a, b, c, d, x[i + 9], 5, 568446438)
      d = this.md5_gg(d, a, b, c, x[i + 14], 9, -1019803690)
      c = this.md5_gg(c, d, a, b, x[i + 3], 14, -187363961)
      b = this.md5_gg(b, c, d, a, x[i + 8], 20, 1163531501)
      a = this.md5_gg(a, b, c, d, x[i + 13], 5, -1444681467)
      d = this.md5_gg(d, a, b, c, x[i + 2], 9, -51403784)
      c = this.md5_gg(c, d, a, b, x[i + 7], 14, 1735328473)
      b = this.md5_gg(b, c, d, a, x[i + 12], 20, -1926607734)

      a = this.md5_hh(a, b, c, d, x[i + 5], 4, -378558)
      d = this.md5_hh(d, a, b, c, x[i + 8], 11, -2022574463)
      c = this.md5_hh(c, d, a, b, x[i + 11], 16, 1839030562)
      b = this.md5_hh(b, c, d, a, x[i + 14], 23, -35309556)
      a = this.md5_hh(a, b, c, d, x[i + 1], 4, -1530992060)
      d = this.md5_hh(d, a, b, c, x[i + 4], 11, 1272893353)
      c = this.md5_hh(c, d, a, b, x[i + 7], 16, -155497632)
      b = this.md5_hh(b, c, d, a, x[i + 10], 23, -1094730640)
      a = this.md5_hh(a, b, c, d, x[i + 13], 4, 681279174)
      d = this.md5_hh(d, a, b, c, x[i + 0], 11, -358537222)
      c = this.md5_hh(c, d, a, b, x[i + 3], 16, -722521979)
      b = this.md5_hh(b, c, d, a, x[i + 6], 23, 76029189)
      a = this.md5_hh(a, b, c, d, x[i + 9], 4, -640364487)
      d = this.md5_hh(d, a, b, c, x[i + 12], 11, -421815835)
      c = this.md5_hh(c, d, a, b, x[i + 15], 16, 530742520)
      b = this.md5_hh(b, c, d, a, x[i + 2], 23, -995338651)

      a = this.md5_ii(a, b, c, d, x[i + 0], 6, -198630844)
      d = this.md5_ii(d, a, b, c, x[i + 7], 10, 1126891415)
      c = this.md5_ii(c, d, a, b, x[i + 14], 15, -1416354905)
      b = this.md5_ii(b, c, d, a, x[i + 5], 21, -57434055)
      a = this.md5_ii(a, b, c, d, x[i + 12], 6, 1700485571)
      d = this.md5_ii(d, a, b, c, x[i + 3], 10, -1894986606)
      c = this.md5_ii(c, d, a, b, x[i + 10], 15, -1051523)
      b = this.md5_ii(b, c, d, a, x[i + 1], 21, -2054922799)
      a = this.md5_ii(a, b, c, d, x[i + 8], 6, 1873313359)
      d = this.md5_ii(d, a, b, c, x[i + 15], 10, -30611744)
      c = this.md5_ii(c, d, a, b, x[i + 6], 15, -1560198380)
      b = this.md5_ii(b, c, d, a, x[i + 13], 21, 1309151649)
      a = this.md5_ii(a, b, c, d, x[i + 4], 6, -145523070)
      d = this.md5_ii(d, a, b, c, x[i + 11], 10, -1120210379)
      c = this.md5_ii(c, d, a, b, x[i + 2], 15, 718787259)
      b = this.md5_ii(b, c, d, a, x[i + 9], 21, -343485551)

      a = this.safe_add(a, olda)
      b = this.safe_add(b, oldb)
      c = this.safe_add(c, oldc)
      d = this.safe_add(d, oldd)
    }
    return this.Array(a, b, c, d)
  },
  /*
 * These functions implement the four basic operations the algorithm uses.
 */
  md5_cmn(q, a, b, x, s, t) {
    return this.safe_add(this.bit_rol(this.safe_add(this.safe_add(a, q), this.safe_add(x, t)), s), b)
  },
  md5_ff(a, b, c, d, x, s, t) {
    return this.md5_cmn((b & c) | ((~b) & d), a, b, x, s, t)
  },
  md5_gg(a, b, c, d, x, s, t) {
    return this.md5_cmn((b & d) | (c & (~d)), a, b, x, s, t)
  },
  md5_hh(a, b, c, d, x, s, t) {
    return this.md5_cmn(b ^ c ^ d, a, b, x, s, t)
  },
  md5_ii(a, b, c, d, x, s, t) {
    return this.md5_cmn(c ^ (b | (~d)), a, b, x, s, t)
  },

  /*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
  safe_add(x, y) {
    var lsw = (x & 0xFFFF) + (y & 0xFFFF)
    var msw = (x >> 16) + (y >> 16) + (lsw >> 16)
    return (msw << 16) | (lsw & 0xFFFF)
  },

  /*
 * Bitwise rotate a 32-bit number to the left.
 */
  bit_rol(num, cnt) {
    return (num << cnt) | (num >>> (32 - cnt))
  }
}

export default md5
